Thank you for continuing to post valuable information here MissHer.  I found a rather complicated, but important explanation as to why the oxidation/nitration of potassium channels is a critical factor in Alzheimer's disease.

Oxidation of KCNB1 potassium channels triggers apoptotic integrin signaling in the brain

Oxidative modification of the voltage-gated potassium (K+) channel KCNB1 promotes apoptosis in the neurons of cortex and hippocampus through a signaling pathway mediated by Src tyrosine kinases.